mass air upgrade for accent
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mass air upgrade for accent
I changed my mass air meter from a shark today to my accent. I have noticed a definate increase in power. I hope to goto the track soon to see for sure about the increase. wondering if anyone else has tried the same swap? The meter from the shark is much larger than the stock accent unit. With a larger throttle body from the same car and possible injecters the increase will be even better I hope!
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From: Rancho Palos Verdes, CA
Vehicle: 2008 Toyota Prius 2006 Suzuki SV650S
It all depends...does the ECU see the increased air flow? Does the ECU know the MAF has been changed? Or is the ECU making calculations based on the stock MAFS...
Basically, even though you swapped mafs, the ECU may be thinking you have the standard maf. MAF's are carefuly calibrated. Installing a bigger one, you could be passing much more air than the ECU thinks. As long as it is within reason, the O2 sensor will detect a lean condition, and the ECU will dump more fuel, thus more power. But the key here is with reason. You may be flowing so much more air, that the stock ECU cannot compenstate. You will then run lean, which will cause detonation, then the computer will try to retard the timing, causing a loss of power, or, if the ECU cannot retard the timing enought...a blown engine.
Damn...I gotta get my hands on an Accent to try this trick with my computer hooked up. Then we could tell if the ECU really sees the increase in air....
Any Accent Owners in the LA area wanna hook up with me?
Basically, even though you swapped mafs, the ECU may be thinking you have the standard maf. MAF's are carefuly calibrated. Installing a bigger one, you could be passing much more air than the ECU thinks. As long as it is within reason, the O2 sensor will detect a lean condition, and the ECU will dump more fuel, thus more power. But the key here is with reason. You may be flowing so much more air, that the stock ECU cannot compenstate. You will then run lean, which will cause detonation, then the computer will try to retard the timing, causing a loss of power, or, if the ECU cannot retard the timing enought...a blown engine.
Damn...I gotta get my hands on an Accent to try this trick with my computer hooked up. Then we could tell if the ECU really sees the increase in air....
Any Accent Owners in the LA area wanna hook up with me?
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I check the hyundai shop manual and the two mass air meters send the same voltage to the ecu. I figured that if they operate on the same voltage levels then the two should corespond and fuction. Its not perfect my check engine light is on now but the car still pulls harder than it did with the stock meter. I still have a few bugs to work out. wish I was closer to you random would love to see what you comp says. Maybe with the throttle body and the injecters from the same car it would help.
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Joined: May 2001
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From: Rancho Palos Verdes, CA
Vehicle: 2008 Toyota Prius 2006 Suzuki SV650S
Okay, here's the deal. MAFS work by density. They don't actually measure air volume, they measure density. SO...the computer is basing it's figures on the correct density figures from the maf...
however, you are flowing more air, at a lower pressure (less dense) than the computer thinks. If you original MAF was say 2" diameter and your new one was 3" diameter. the 3" MAF will register a lower density for the same volume of air, so ECU thinks you have a 2" MAF and are just flowing a very small bit of air.
This is really a dangerous mod. Basically you are forcing your ECU to run lean. Which will lead to detonation.
If you had an SAFC..that would alow you to turn up the "air" voltage signal to the ECU, so the ECU would know you are flowing more air...you would be in business. The question is...how MUCH more air are you flowing. That is going to be hard to tell. Also..from what I have read, the MAF voltage signal is not linear. So just stepping up the voltage .5V or whatever will not work across all engine RPM.
I'm going for help on this one....
however, you are flowing more air, at a lower pressure (less dense) than the computer thinks. If you original MAF was say 2" diameter and your new one was 3" diameter. the 3" MAF will register a lower density for the same volume of air, so ECU thinks you have a 2" MAF and are just flowing a very small bit of air.
This is really a dangerous mod. Basically you are forcing your ECU to run lean. Which will lead to detonation.
If you had an SAFC..that would alow you to turn up the "air" voltage signal to the ECU, so the ECU would know you are flowing more air...you would be in business. The question is...how MUCH more air are you flowing. That is going to be hard to tell. Also..from what I have read, the MAF voltage signal is not linear. So just stepping up the voltage .5V or whatever will not work across all engine RPM.
I'm going for help on this one....
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Greetings,
You are confusing the voltage modal range for actual output, which is causing A: your check engine light, and likely B: your car is running really lean.
Let's start by explaining WTF a modal range is, versus actual output:
The MAF sensors in all the current Hyundai cars are a 5-volt system. Each sensor has four wires -- a ground, a 12VDC, a 5VDC send, and a 5VDC return. Since they're all four wire, and they are all based on the same electrical needs (12v and 5v respectively), then they appear on the outside to be interchangeable.
And they are, but only to a certain extent...
A MAF sensor "measures" the air just as Random said -- not necessarily by how MUCH is going past, but by actually how dense the air is. A small wire in the sensor is heated, and passing air cools that wire off. The sensor measures how much electricity is needed to keep the wire at constant temperature, and THIS is how the car knows how much air is coming into the car. You also need a temperature sensor so the MAF knows how hot the air is -- obviously, hot air isn't going to cool as much smile.gif so the car needs to know ambient temperature too.
Ok, so are you with me? Car figures out how much air is coming in by "measuring it" with the MAF sensor.
The car then makes the next very important step, which is making sure there is GAS to go with the air. The onboard computer has a cool little lookup table where it says "For every X amount of air coming in, add Y amount of fuel". It's a bit more technical than that, but you get the idea. There is a very specific amount of fuel that must be mixed with air -- too much fuel, and you get less power AND less fuel mileage. Too little fuel, and you get less power AND higher engine temperatures. The general standard is 14.7 units of air for every unit of gasoline.
So, you still with me? Computer knows exactly how much air is coming in from the MAF sensor, so it knows exactly how much fuel to send to the motor so everything runs perfect.
Now here comes the problem:
MAF sensors are not all alike. Yeah, they run on 12 and 5 volts, but they don't send BACK the same information. Let me use a quick example: MAF sensors send a certain AMOUNT of voltage when a certain amount of air is going by.
10 lbs of air per minute might make the MAF sensor send back 2 volts.
20 lbs of air per minute might make that same MAF sensor send back 2.3 volts
40 lbs of air per minute might make the sensor report back with 4 volts.
It's not linear... Twice as much air does NOT equal twice as much voltage being sent back. 5 volts goes in, but only a certain amount comes back OUT dependant on the air. Each MAF type is different between models, the amount of voltage they send back isn't the same between models. Each MAF model will have different amounts of air it can report (an Accent MAF cannot see as much air as a Tiburon MAF) and also reports different voltages... An Accent MAF may report that 40lbs of air is equal to 4 volts, but a Tiburon MAF may say 40lbs of air is only 2.8 volts.
So here's the problem...
Your Accent computer is expecting voltage from an Accent MAF sensor. It knows that the Accent MAF sensor will tell it 40 pounds of air = 4 volts, and it knows exactly how much fuel to send to make the car run correctly. When you changed to a Tiburon MAF, you've screwed up the reporting system. The computer is getting only 2.8 volts instead, and thus thinks a LOT less air is coming into the car...
End result? The car doesn't send enough fuel. You get heat issues from lean conditions, you melt your cat, you get less power, and you eventually can torch a ringland / burn valves or even melt a hole in a piston. It likely will not come to that, or at least we hope...
What Random was trying to tell you is, you need to devise some method of "translating" the Tiburon MAF voltage to something the Accent computer can understand. The absolute best way is to buy an Apexi SuperAFC device. It's expensive ($270 on a good sale), but will do the job very well.
I'm very sure you're getting better performance from the larger 60mm MAF sensor, but the damage you are doing to your car is not a good thing. You will want to do something about the fuel soon or you'll start having expensive problems later in life.
And no, a fuel pressure raise will not fix the problem. Fuel pressure has a very "broad" effect, and doesn't work for inequally calibrated MAF sensors.
You are confusing the voltage modal range for actual output, which is causing A: your check engine light, and likely B: your car is running really lean.
Let's start by explaining WTF a modal range is, versus actual output:
The MAF sensors in all the current Hyundai cars are a 5-volt system. Each sensor has four wires -- a ground, a 12VDC, a 5VDC send, and a 5VDC return. Since they're all four wire, and they are all based on the same electrical needs (12v and 5v respectively), then they appear on the outside to be interchangeable.
And they are, but only to a certain extent...
A MAF sensor "measures" the air just as Random said -- not necessarily by how MUCH is going past, but by actually how dense the air is. A small wire in the sensor is heated, and passing air cools that wire off. The sensor measures how much electricity is needed to keep the wire at constant temperature, and THIS is how the car knows how much air is coming into the car. You also need a temperature sensor so the MAF knows how hot the air is -- obviously, hot air isn't going to cool as much smile.gif so the car needs to know ambient temperature too.
Ok, so are you with me? Car figures out how much air is coming in by "measuring it" with the MAF sensor.
The car then makes the next very important step, which is making sure there is GAS to go with the air. The onboard computer has a cool little lookup table where it says "For every X amount of air coming in, add Y amount of fuel". It's a bit more technical than that, but you get the idea. There is a very specific amount of fuel that must be mixed with air -- too much fuel, and you get less power AND less fuel mileage. Too little fuel, and you get less power AND higher engine temperatures. The general standard is 14.7 units of air for every unit of gasoline.
So, you still with me? Computer knows exactly how much air is coming in from the MAF sensor, so it knows exactly how much fuel to send to the motor so everything runs perfect.
Now here comes the problem:
MAF sensors are not all alike. Yeah, they run on 12 and 5 volts, but they don't send BACK the same information. Let me use a quick example: MAF sensors send a certain AMOUNT of voltage when a certain amount of air is going by.
10 lbs of air per minute might make the MAF sensor send back 2 volts.
20 lbs of air per minute might make that same MAF sensor send back 2.3 volts
40 lbs of air per minute might make the sensor report back with 4 volts.
It's not linear... Twice as much air does NOT equal twice as much voltage being sent back. 5 volts goes in, but only a certain amount comes back OUT dependant on the air. Each MAF type is different between models, the amount of voltage they send back isn't the same between models. Each MAF model will have different amounts of air it can report (an Accent MAF cannot see as much air as a Tiburon MAF) and also reports different voltages... An Accent MAF may report that 40lbs of air is equal to 4 volts, but a Tiburon MAF may say 40lbs of air is only 2.8 volts.
So here's the problem...
Your Accent computer is expecting voltage from an Accent MAF sensor. It knows that the Accent MAF sensor will tell it 40 pounds of air = 4 volts, and it knows exactly how much fuel to send to make the car run correctly. When you changed to a Tiburon MAF, you've screwed up the reporting system. The computer is getting only 2.8 volts instead, and thus thinks a LOT less air is coming into the car...
End result? The car doesn't send enough fuel. You get heat issues from lean conditions, you melt your cat, you get less power, and you eventually can torch a ringland / burn valves or even melt a hole in a piston. It likely will not come to that, or at least we hope...
What Random was trying to tell you is, you need to devise some method of "translating" the Tiburon MAF voltage to something the Accent computer can understand. The absolute best way is to buy an Apexi SuperAFC device. It's expensive ($270 on a good sale), but will do the job very well.
I'm very sure you're getting better performance from the larger 60mm MAF sensor, but the damage you are doing to your car is not a good thing. You will want to do something about the fuel soon or you'll start having expensive problems later in life.
And no, a fuel pressure raise will not fix the problem. Fuel pressure has a very "broad" effect, and doesn't work for inequally calibrated MAF sensors.
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Hey red I talk to APEXI and they said they weren't sure if the SUPER AFC would work with the Hyundai computer or not! Go figure! They said that it could possibly work it should hook up but the actual tuneing of the car will be the hard part! I even called HVE and they didn't know either. So what do you think??? I an going to buy one this week and see what the hell happens but I wanted to know what you thought about this situation now!!! Anything will help I'm sure Thanks!!
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Heehee...
I would post a picture of the S-AFC in my Tiburon, but my webspace provider is down so sad.gif
Any car that uses an OBD2 computer system can accept the S-AFC, just so long as you have the patience to match up the wires. And I do mean _any_... The S-AFC needs 6 signals:
12VDC Positive
12VDC Ground
RPM Signal Input
Air Metering Device Input
Air Metering Device Output
Throttle Position Sensor Input
That's it. If your car has those (which ever car made after 1996 does) then you're set. The S-AFC can recognize MAF, MAP, Karmon/Vortex, and Flapper sensors. You could theoretically install one of these S-AFC devices into a Geo Metro if you really want, or maybe a Ford Aspire, or an Audi S4 biturbo.
It's a very extensible unit, the wiring only needs to be deciphered by the person installing it.
So in other words, it will work with your Accent. Just finding someone with the appropriate wiring schematics for an Accent will be the key. You could actually find all the data you need by cruising the HMA Webtech online system and searching through the electrical diagrams. That's actually how Onpol from FXTreme figured it out.
I would post a picture of the S-AFC in my Tiburon, but my webspace provider is down so sad.gif
Any car that uses an OBD2 computer system can accept the S-AFC, just so long as you have the patience to match up the wires. And I do mean _any_... The S-AFC needs 6 signals:
12VDC Positive
12VDC Ground
RPM Signal Input
Air Metering Device Input
Air Metering Device Output
Throttle Position Sensor Input
That's it. If your car has those (which ever car made after 1996 does) then you're set. The S-AFC can recognize MAF, MAP, Karmon/Vortex, and Flapper sensors. You could theoretically install one of these S-AFC devices into a Geo Metro if you really want, or maybe a Ford Aspire, or an Audi S4 biturbo.
It's a very extensible unit, the wiring only needs to be deciphered by the person installing it.
So in other words, it will work with your Accent. Just finding someone with the appropriate wiring schematics for an Accent will be the key. You could actually find all the data you need by cruising the HMA Webtech online system and searching through the electrical diagrams. That's actually how Onpol from FXTreme figured it out.